Oxalacetic acid bis(2-substituted-2,2-dinitroethyl)esters

ABSTRACT

Oxal acetic acid esters of the formula   WHERE R represents NO2, H, F and CH3 are produced by the reaction of acetylenedicarboxylic acid, water and an alcohol of the formula   IN FUMING SULFURIC ACID. These compounds find use as high-energy plasticizers.

United States Patent Marcus Mar. 18, 1975 W] OXALACETIC ACID BIS(2-SUBSTITUTED-2.2-DINITRO- ETHYLlESTERS [7'5] Inventor: Henry J. Marcus. West CoVina.

Calif.

{73] Assignee: The United States of America as represented by the Secretary of the Navy, Washington. DC.

[22 Filed: Nov. 6, 1970 1:1 Appl. No.: 97,438

OTHER PUBLICATIONS Langes Handbook of Chemistry, Handbook Publishers. lnc. Sandusky, Ohio, 6th Ed. 1946, p. 446 'l'PlSlHZS.

PJ'IHIUI') Emnziuer-Leland A. Sebastian Attorney, Agent. or Firm-R. S. Sciascia; J. A. Cooke [57] ABSTRACT Oxal acetic acid esters of the formula ca co cs 9-12 where R represents N0 H. F and CH are produced by the reaction of acetylenedicarhoxylic acid, water and an alcohol of the formula HOCHZ C R in fuming sulfuric acid. These compounds find use as high-energy plasticizers.

4 Claims, N0 Drawings OXALACETIC ACID BIS(2-Sl BSTITUTED-2.2-DINITROETHYIJES- TERS BACKGROUND OF THE INVENTION This invention relates generally to plasticizers and more particularly to high energy carboxylic acid esters and to a process for the preparation thereof.

The use of plasticizers in both explosive and propellant compositions is widely known. There has long been a search for plasticizers which besides being thermally stable have a relatively high energy which can be released on detonation so that the propellant or explosive composition will have maximum energy release per unit of weight. It is also often desirable to have plasticizers which are miscible with other plasticizers so that mixtures of plasticizers can be used in a composition. The use of such mixtures enables the preparation of a final product which will have a lower melting point than any of the components individually and will. therefore. enhance low-temperature properties of the system.

SUMMARY OF 'IHl-I lNVl-IN'I'ION Accordingly. it is an object of this invention to provide high energy. thermally stable esters of oxalacetic acid.

Another object of the present invention is to provide plasticizers which can be used in propellant and explosive compositions.

Still another object of the instant invention is to provide a method for the preparation of esters of oxalacetic acid.

These and other objects of the invention are accomplished by providing compounds of the formula 4s ca co cs c R where R is selected from the group consisting of H, F, N0 and CH which are prepared by reacting acetylenedicarboxylic acid with an alcohol of the formula EMBODIMENT The esters of oxalacetic acid are prepared according to the following reaction sequence:

110 c c c c0 11 ricer! c a ac co ca t n o c co ca c a CH CO CH (.1 R

where R is selected from the group consisting of H, F. N0 and CH Thus, acetylenedicarboxylic acid is reacted with the corresponding alcohol in the presence of sulfuric acid and, after the reaction has proceeded for a while water is added. It is believed that the reaction proceeds thru the bracketed intermediate but applicant does not wish to be bound by this mechanism.

Since explosive materials are involved in the reaction the temperature throughout should vary between about 5C and 40C.

Generally, one charges the sulfuric acid, preferably a mixture ofsulfuric acid and fuming sulfuric acid. into a flask and then cools the contents of the flask down to room temperature. The acetylenedicarboxylic acid is added portionwise with stirring. When about all of the acid is dissolved the alcohol is added. At this point it is preferable to cool the contents of the flask before addition of the alcohol. The mixture is then allowed to stand for a number of days before it is quenched. On standing, with scratching, if necessary, the desired product crystallizes out. If desired the product may be further purified by recrystallization.

The general nature of the invention having been set forth. the following example is presented as a specific illustration thereof. It will be understood that the invention is not limited to the specific example but is susceptible to various modifications that will be recognized by one of ordinary skill in the art.

EXAMPLE A 500 ml flask was charged with ml concentrated sulfuric acid and 100 ml 20-23% fuming sulfuric acid. The solution was cooled to room temperature, and 22.8g (0.02 mole) acetylenedicarboxylic acid was added in portions with magnetic stirring. The temperature rose to about 32C and slight gassing noted. Nearly all of the acid went into solution. After cooling to -15C. 65g (0.60 mole. 95% pure) Z-fluoro-2.2- dinitroethanol was added. A slight rise in temperature was noted and the solution turned red. The solution was allowed to stand at room temperature. After 4 days the reaction mixture was quenched in 1.5 l ice-water. On standing for several hours with occasional scratching, the mixture slowly crystallized. The product was collected on a filter, washed with water until the wash water was no longer acid. and dried in a desiccator. The crude ester weighed 5.0g. m.p. 44-47C. The product was purified by recrystallization from chloroformcarbon tetrachloride, giving colorless crystals melting at 48-49C. Elemental analysis: calcd for C H N O F C, 23.8; H, 1.5; N, 13.9; F, 9.4. Found: C. 22.1; H, 1.6; N, 14.3. F. 10.4.

Similarly 2.2-dinitroethanol. 2.2-dinitropropanol. and 2.2.2-trinitroethanol can be used in place of Z-fluoro-Z.2-dinitroethanol to prepare the corresponding esters.

Obviously. numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described herein.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

l. Oxalacetic acid ester of the formula O=C-C0 CH CR CH CO CH 9 R uocn c R F50 wherein R is selected from the group consisting of H. F, N0 and CH at a temperature between about 5C and 40C in the presence of sulfuric acid.

4. A method according to claim 3 wherein the alcohol is 2-fluoro-2.2-dinitroethanol. 

1. OXALACETIC ACID ESTER OF THE FORMULA
 2. A compound of claim 1 which is oxalacetic acid bis(2-fluoro-2,2-dinitroethyl) ester.
 3. A METHOD OF PREPARING THE COMPOUNDS OF CLAIM 1 AND AN ALCOHOL PRISING CONTACTING ACETYLENEDICARBOXYLIC ACID AND AN ALCOHOL OF THE FORMULA
 4. A method according to claim 3 wherein the alcohol is 2-fluoro-2,2-dinitroethanol. 